Q.2.103 - Elementary Statistics

Question

Cholesterol Levels. According to the National Health and

Control and Prevention, the average cholesterol level for children between $4$ and $19$ years of age is $165\mathrm{mg}/\mathrm{dL}$. A pediatrician who tested the cholesterol levels of several young patients was alarmed to find that many had levels higher than $200\mathrm{mg}/\mathrm{dL}$. The following relativefrequency histogram shows the readings for some patients who had high cholesterol levels.

Use the graph to answer the following questions. Note that cholesterol levels are always expressed as whole numbers.

a. What percentage of the patients have cholesterol levels between $205$ and $209$ , inclusive?

b. What percentage of the patients have levels of $215$ or higher?

c. If the number of patients is $20$ , how many have levels between $210$ and $214$ , inclusive?

Step-by-Step Solution

Answer

a). The percent of patients have cholesterol level between $205$ and $209$ is $0.20$ or $20\%$.

b). The percent of patients have a level of $215$ or higher is, $25\%$.

c). The number of patients have cholesterol level between $210$ and $214$ is, $7$.

Part (a) Step 1: Given Information

The data is given as,

Part (a) Step 2: Explanation

The percent of patients have cholesterol level between $205$ and $209$ is $0.20$ or $20\%$ because the height of third bar is about $0.20$.

Part (b) Step 1: Given Information

The data is given as,

Part (b) Step 2: Explanation

The percent of patients who have a level $215$ or higher is,

$0.20+0.04=0.25\text{ or }25\%$.

Part (c) Step 1: Given Information

The data is given as,

Part (c) Step 2: Explanation

The number of patients has cholesterol levels between $210$ and $214$ is,$0.35\left(20\right)=7$.